I live in Europe and we use a different unit for weight, kilograms (kg), which leaves me puzzled how to interpret the lbs mentioned in the various threads I encounter on this forum. How exactly should I convert these units properly to and fro?

Completely silly! We spent tens of millions of dollars on the conversion in the 1970's. We converted all the highway signs to metric, food containers at the supermarket etc. Everything had imperial and metric listed for a while, then it was abandoned. They spent tens of millions more switching everything back. It was decided that Americans were too stupid to make the switch. We may not be known for being the brightest people in the world, but certainly we can handle metrics!!!!!